Rock-drill



(No Mod-e1.)

T. OFFICER. ROGK DRILL.

No. 580,462. Patented Apr. 13, 1897.

WI NESSES: an INVEN EI Mme. m W

irnn -TATES FFICEQ THOMAS OFFICER, OF CLAREMONT, NEW HAMPSHIRE, ASSIGNOR TO THE SULLIVAN MACHINERY COMPANY, OF SAME PLACE AND CHI- CAGO, ILLINOIS.

ROCK-DRILL.

SPECIFICATION forming part of Letters Patent No. 580,462, dated April 13, 1897.

Application filed August 12, 1896.

To all whom it may concern.-

Be it known that I, THOMAS OFFICER, a resident of Claremont, in the county of Sullivan and State of New Hampshire, have invented a new and useful Improvement in Rock-Drills; and I do hereby declare the following to be a full, clear, and exact description thereof.

My invention relates to rock-drills.

The special form of rock-drill to which my invention is applicable is that in which a cylinder is employed with a piston operating therein and a spiral rifle-bar working in a nut in the piston, together with mechanism at one end of said rifle-bar for permitting of the rotation of the rifle-bar upon the descent of the piston, but holding said rifle-bar from rotation upon the upward stroke of the piston, whereby the piston itself is turned upon the upward stroke.

The present invention relates to an improved form of mechanism for holding the rifle-bar during the upward stroke of the piston and for releasing said mechanism in case the drill-bit should be prevented from turning.

My invention comprises certain new features in this form of mechanism, all of which will be fully hereinafter set forth and claimed.

To enable others skilled in the art to make and use my invention, I will describe the same more fully, referring to the accompanying drawings, in which- Figure l is a sectional view of the upper part of a common form of rock-drill to which my invention has been applied. Fig. 2 is a section on the line 2 2, Fig. 1. Fig. 3 is a view of the friction-ring or segments with the rifle-bar projecting therefrom. Fig. 4 is a view of one of the rollers. Figs. 5 and 6 are modified forms of my invention.

Like letters indicate like parts in each of the figures.

As the form of rock-drill to which my invention is applicable is so well known, I have not deemed it necessary to illustrate the valve mechanism and the lower part of the apparatus, as there are different forms of valve mechanism which may be used, and such valve mechanism forms no part of my invention.

Serial No. 602,499. (No model.)

The letter a represents the upper portion of a suitable cylinder having the piston-chamher a therein, together with the valve-controlled ports (not shown) for admitting steam to the ends of said piston-chamber. YVit-hin the chamber a is the piston 19, whose rod extends down therefrom and which has attached thereto a suitable drill-bit. The piston 19 has the cavity 0 formed therein, adapted to receive the rifle-bar d. This rifle-bar has the spiral grooves (1 formed therein, said grooves engaging with the rifle-bar nut e, secured within -a recess 6 at the upper end of said piston.

The upper end of the rifle-bar d passes through an opening in the division-collar f, and on the upper end of said rifle-bar is a ratchet-head g. This ratchet-head g has the teeth 9 formed in its circumference, said teeth having the curved recesses g and the inclines g leading therefrom to the periphery on a preferably straight line. The curved recesses g are adapted to receive the rollers h h.

Surrounding the ratchet-head g and restin g upon the division-collar f is the frictionring '0'. Said friction-ring may be formed. in separate halves or segments t" 2' or may be formed in one piece. I prefer to employ the divided ring, however, for the reasons more fully hereinafter set forth. The friction-ring has the groove 1' formed therein and the openings t leading from said groove to the interior of said ring. Secured at j within said groove i are the springs j, said springs being adapted to bear against the rollers 72 h and normally hold them within the curved seats 9 of the ratchet-teeth g. Formed on the inner face of the ring 2' are the inclines k. Resting on the ring 2' is the head Z, sufficient space being left between said head and the ratchet-head g to permit of the turning of said ratchet'head without friction. Passing through the head Z are the rods m, the

lower ends of said rods being held within the lower head of the cylinder and springs or being interposed between said head Z and nuts 0 at the upper end of said rods. In this manner by tightening the nuts 0 the head Z may be forced down onto the ring 2'.

WVhen my improved rock-drill is in operation, as the piston b descends the rifle-bar cl IOO will turn in the direction of the arrow in Fig; 2. This is due to the fact that the rollers h h are free to move into the deepest part of the incline, which is equal to the diameters of said rollers, whereby the said rollers can pass over the tops of the teeth, pushing back the springs as they move. The springs will be forced back as the rollers pass over the points of the teeth, but said springs will force said rollers down onto the next teeth. On the upward stroke, however, of the piston b the rifle-bar is prevented from turning by means of the rollers h h. The roller 71 comes in contact with the incline k and prevents the rotation-of the rifle-bar. By having the segments t" i I obtain more friction, as the said segments are forced by the action of the rollers on the inclines against the inner face of the case containing said segments. This does not occur where the ring is made in one piece. I prefer to employ an odd number of teeth in the ratchet-head, so that the roller h rests in the bottom of a tooth the same as the roller h, but does not come against the incline 7c. The object of this is to catch the ratchet at less than the whole travel of the tooth. If it travels half a tooth, the roller h will stop it. If it travels a whole tooth, the roller it will catch the ratchet. The rollers work very easily on the teeth, and instead of sliding in the manner of the pawl they roll from one tooth to another, which gives less wear. There is also very little wear upon the rollers. The rifle-bar being held against rotation in this way, upon the descent of the piston the piston and the rifle-bar nut 6 will be compelled to turn. In case, however, the drill-bit should be held from turning in the rock for any reason and it is impossible for it to turn then sufficient pressure will be exerted to move the ring or parts 2', whereby the strain on the drill parts is not too great and the piston ascends without injury to the drill parts.

In Fig. 5 I have shown a modified form of my apparatus in which, instead of having the springs j bear directly upon the rollers h 7t, I employ a lever r, pivoted at 7", which bears against said rollers. The inner end of the lever 0" has the lug T with which the end of the spring engages.

In Fig. 6 I dispense with the springs 02, interposed between the head Z and the nuts 0 on the rods m, and use a central spring .9, which bears directly upon the plate t. A set-screw a, passing down through the head a, regulates the tension of said spring .9, whereby the plate 6 can be forced down upon the frictional ring or segments, .or can be loosened to pen mit the friction-ring to turn readily, which is desirable in some cases where the drill is to be used for broaching, in which case the piston is not revolved.

lVhat I claim as my invention, and desire to secure by Letters Patent, is

1. In a rock-drill, the combination with a suitable cylinder having a reciprocating piston therein, of a spiral rifle-bar engaging'said piston, a ratchet-head on said rifle-bar, a friction-ring composed of segments surrounding said ratchet-head, a head pressing down upon said friction-ring, rollers engaging the teeth of said ratchet-head and the inner face of said friction-ring, and springs acting upon said rollers, substantially as set forth.

2. In a rock-drill, the combination with a suitable cylinder having a reciprocating piston therein, of a spiral rifle-bar engaging-said piston, a ratchet-head on said rifle-bar, a friction-ring composed of segments surrounding said ratchet-head, a head pressing down upon said friction-ring, rollers engaging the teeth of said ratchet-head, and inclines on the inner face of said friction-ring, substantially as set forth.

3. In a rock-drill, the combination with a suitable cylinder having a reciprocating piston therein, of a rifle-bar engaging said piston, a ratchet-head on said rifle-bar, a fric tion-ring composed of segments surrounding said ratchet-head, a head pressing down upon said friction-ring, rollers engaging the teeth of said ratchet-head and inclines on the inner face of said ring, and springs acting upon said rollers, substantially as set forth.

4. In a rock-drill, the combination with a suitable cylinder having a reciprocating piston therein, of a rifle-bar engaging said piston, a ratchet-head on said rifle-bar, a friction-ring composed of segments surrounding said ratchet-head, a head pressing down upon said friction-ring, rollers engaging the teeth of said ratchet-head and inclines on the inner face of said ring, and springs secured within a groove formed in said ring and adapted to engage said rollers, substantially as set forth.

In testimony whereof I, the said THOMAS OFFICER, have hereunto set my hand.

THOMAS OFFICER.

Witnesses:

H. W. PARKER, E. J. TENNEY. 

